   [conn-data]
   (let [jar-paths (util/find-driver-jars)
         jar-urls (map (fn [p] (java.net.URL. "file" "" p)) jar-paths)]
-    (connect-with-urls! conn-data jar-urls)))
+    (if (> (count jar-urls) 0)
+      (connect-with-urls! conn-data jar-urls)
+      nil)))
 
 
 (defn connect-with-auto!

      (let [^java.sql.Connection conn (if (not (blank? conn-jar))
                                        (connect-with-path! conn-data)
                                        (connect-with-auto! conn-data))]
        (.setAutoCommit conn false)
        {:conn conn})
      (catch java.security.PrivilegedActionException e {:conn nil
                                                        :msg (str e)
                                                        :desc (exception-to-stacktrace e)})



(defn connect-with-urls!
  "Try to connect using URLClassLoader initialized with given url.

  Parameters:

  - conn-data - defines connection metadata,
  - urls - nonempty coll of urls.
  "
  [^clojure.lang.IPersistentMap conn-data urls]
  (assert (not= urls nil))
  (assert (> (count urls) 0))
  (let [conn-class (conn-data "class")
        conn-str (conn-data "jdbc-conn-str")
        url-class-loader (java.net.URLClassLoader. (into-array urls))
